Quck answer
To test a coil or spark plug on a lawnmower engine, follow these steps:
1. Remove the spark plug wire from the spark plug.
2. Use a spark plug socket to remove the spark plug from the engine.
3. Inspect the spark plug for any signs of damage or wear.
4. If the spark plug appears to be in good condition, reconnect it to the spark plug wire.
5. Ground the spark plug by touching the metal threads to a metal surface on the engine.
6. Pull the starter cord and observe the spark plug for a blue spark.
7. If there is no spark or the spark is weak, the coil may be faulty and needs to be replaced.
8. If the spark is strong, the coil is functioning properly, and the issue may lie elsewhere in the engine.
When it comes to starting and running a lawnmower, three main components are crucial: air, fuel, and spark. While it’s easy to check for a clogged air filter or fill the fuel tank, determining whether the ignition coil is generating the necessary electrical spark to ignite the air and fuel mixture can be confusing. Luckily, most small engines found in lawnmowers are relatively simple, making it easier to assess the health of the ignition system using a few basic tools.
Step 1
To access the ignition coil, open the lawnmower’s hood or cover. Locate the coil on the motor by tracing the spark plug cable.
Step 2
Disconnect the spark plug cable from the spark plug and remove the spark plug itself. Keep it aside for now. Pull the kill switch wire of the ignition coil directly off the coil.
Step 3
Insert either a spark tester tool or a functioning replacement spark plug into the spark plug wire. Ground the spark tester or spark plug by placing it against the metal housing of the motor.
Step 4
Take a short length of rope and wrap it around the flywheel, which is the round disk-shaped component above the motor. This rope will enable you to rotate the flywheel at a faster speed than by manual spinning.
Step 5
Switch on the lawnmower’s ignition and pull the rope to spin the flywheel. Observe the spark tester or spark plug and look for a spark between the electrodes. If you see a spark, the ignition coil is functioning correctly. If there is no spark, you will need to replace the ignition coil.
Step 6
Turn off the ignition switch and remove the spark plug or spark tester from the spark plug wire. Reinstall the original spark plug and place the spark plug wire back onto the motor.
Step 7
Re-wrap the rope around the flywheel and switch on the lawnmower’s ignition. Pull the rope to spin the flywheel and observe the original spark plug for a spark. If there is a spark, the spark plug is functioning correctly. If there is no spark, you will need to replace the spark plug.
